The V880 is a VME-based system timing module, used to distribute picosecond-precision timing pulses across physically distributed facilities. The V880 receives a 155.52 MHz (OC3 rate) fiberoptic master timing signal and outputs eight local triggers. A typical facility timing system would consist of one master optical signal generator, fiberoptic fanouts as needed, and several to hundreds of V880 timing units.
Test features include:Master fiberoptic timing signal generators are available.
FUNCTION | 8-channel digital timing generator |
DEVICE TYPE | 16-bit register-based VME slave; A16:D16 Implements 256 16-bit registers in the VME 16-bit addressing space |
INPUTS | Primary timing input: 155.52 Mbps, biphase-encoded data stream, 1310 or 1550 nm, -20 to -28 dBm, APC/SC bulkhead connector Electrical test trigger, +1 V nominal threshold, 50Ω termination, SMB connector |
OUTPUTS | Reference timing pulse, +1.75 V nominal into external 50Ω load, 180 ns nominal width, 700 ps nominal rise/fall, SMB connector Test output, sample of software-selected output channel pulse; +1 V nominal into 50Ω, SMB connector Eight channel outputs, 180 ns pulse each, available as electrical or optical outputs in groups of four channels Electrical outputs are +4 V nominal into 50Ω, transformer isolated, 750 ps nominal risetime, SMB connectors Optical outputs are 850 nm, 500 µW nominal, 500 ps max risetime, ST 62/125 µm multimode connectors |
DELAYS | Eight channels; each channel includes a VME-programmable 128-bit pattern match array, a 128-bit pattern mask array, and a 0 to 3
second range digital delay generator with 1 ps LSB resolution Each channel is triggered when its programmed pattern match aligns with the time data fields in the master fiberoptic input signal A ninth reference channel is provided, with pattern match capability but no programmable delay |
ACCURACY | Jitter is below 15 [25] ps RMS measured over 10 seconds or less Delay accuracy is ±250 [500] ps; resolution 1 ps; monotonicity 40 [100] ps Insertion delay is 96.0 ns relative to the end of frame sync Reference pulse delay is 63 ns ±450 [750] ps Temperature drift is below 1 [2.5] ps/°C Optical power sensitivity is below 15 [50] ps/db, -20 to -28 dBm |
OPERATING TEMPERATURE | 10 to 35°C |
CALIBRATION INTERVAL | One year |
POWER | Standard VME supplies: +5 V: 1.75 A +12 V: 0.4 A -12 V: 0.6 A |
INDICATORS | LEDs indicate VME access, channel trigger, and phaselock |
PACKAGING | 6U single-wide VME module |
CONFORMANCE | ANSI/VITA 1-1994 (R2002) VMEbus spec |
Block Diagram: V880 delay generator for facility timing systems
V880: 8-channel VME delay generator for facility timing systems